Intro

In How to find is a site up (or is blocked by your local ISP), I focused on verifying if an IP/Web site is reachable.  This helps verifying if your ISP (or the BNL firewall for example) is blocking a site or if the site really exists. But of course, there is always the possibility to have "a" site reachable but not the right one (i.e. the DNS records are not what you think they should be). Here are a few tools for you

Tools

Many sites provides similar services, I provide a few here as examples and quick links:

• ViewDns has a DNS propagator lookup tool, accessible via a URL like http://www.viewdns.info/propagation/?domain=MyURL.I.Want.to.check (for example, http://www.viewdns.info/propagation/?domain=www.star.bnl.gov) showing the value of the DNS records from several DNS server across the world. Very handy as information does not propagate at the same speed everywhere ...
• For a more in depth check and , network-tools provides a set of utilities as well. One is the DNS record check taking the form http://network-tools.com/default.asp?prog=dnsrec&host=MyURL.I.Want.to.check (ex: http://network-tools.com/default.asp?prog=dnsrec&host=www.star.bnl.gov)
• MxToolBox (checks MX records), also has a URL based tool of the form more http://mxtoolbox.com/SuperTool.aspx?action=mx:MyURL.I.Want.to.check (ex: http://mxtoolbox.com/SuperTool.aspx?action=mx:www.star.bnl.gov) giving information on the MX records themselves (this is potentially a different information than the DNS records).

Hope those are useful ...